Gut Site and Gut Morphology Predict Microbiome Structure and Function in Ecologically Diverse Lemurs

Area of Science:

• Primate biology
• Microbiome research
• Gastrointestinal ecology

Background:

• Wildlife gut microbiota studies often use fecal samples to represent the entire gastrointestinal tract.
• Lemurs exhibit diverse feeding ecologies and gut morphologies, particularly in their large intestines, related to fibrous food consumption.

Purpose of the Study:

• To compare microbiome structure and predicted metagenomic function across different gastrointestinal tract segments (stomach, small intestine, cecum, colon) in lemurs.
• To investigate how host feeding ecology and gut morphology influence gut microbial communities.

Main Methods:

• Analysis of stomach, small intestinal, cecal, and colonic samples from 52 lemurs across seven genera.
• Comparison of microbiome diversity, variability, membership, and predicted metagenomic function.
• Correlation of microbial patterns with host gut morphology, particularly fermentation capacity (small to large intestine length ratio).

Main Results:

• Microbiome diversity, variability, membership, and function significantly differed between the upper and lower gut segments.
• These patterns were modulated by fermentation capacity, not minimally by total gut length.
• Hosts with limited fermentation capacity had homogenized gut microbiomes, while those with expanded capacity showed greater diversity and abundant Ruminococcaceae in the lower gut.

Conclusions:

• Gut microbial communities are regionally structured along the gastrointestinal tract in lemurs.
• Fermentation capacity is a key factor shaping lower gut microbiome composition and function.
• The need to process fibrous foods influences the evolution of both gut morphology and associated microbial communities in primates.